Various load-carrying support devices are known which are adapted to be directly mounted to a surface, and thereafter used for supporting articles. These types of devices are available in a wide array of configurations and styles, and have proven to be extremely popular consumer items. One of the features of such support devices which enhances their versatility by permitting secure and stable mounting of the device on many different types of surfaces is the provision of one or more backing members for the device formed of fibrous material such as wood. The provision of such wooden backing members permits the support device to be readily affixed to a surface with suitable adhesive typically provided on the backing member, with the adhesive providing secure and stable mounting of the device. Examples of support devices of this description can be found in U.S. Pat. No. 3,504,878.
In forming support devices of this description, it has heretofore been the practice to position the wooden backing member for the device along the periphery of the mold cavity of a suitable plastic molding machine, and to thereafter fill the mold cavity with plastic so that the plastic bonds to the backing member as the article is formed. An injection molding machine is typically employed for this purpose, with one or more wooden backing members positioned along the periphery of the mold cavity of the machine so that when molten plastic is introduced into the cavity the desired plastic article having the backing member bonded thereto is formed.
U.S. Pat. No. 4,025,258 illustrates and describes an apparatus for forming a support device having a backing member as described above. The apparatus disclosed in this patent has proven to be very commercially successful, and has obviated problems previously encountered with positioning the backing members for the plastic articles within the plastic mold cavity by hand. The apparatus of the above patent discloses a punch and die mechanism which is associated with one of the male and female mold portions of the injection molding machine for automatically cutting a wooden backing member from a piece of wood, and thereafter advancing the severed backing member into position along the periphery of the mold cavity so that it is bonded to the plastic article formed in the desired fashion.
The apparatus of the above patent is adapted to receive discrete strips of wood from which the backing members for the finished products are cut during the operation of the apparatus. The strips of wood are positioned intermediate the punch and cutting edge of the punch and die mechanism of the apparatus for each cycle of the machine, so the wooden backing members are cut and thereafter molded to the plastic article. After each strip of wood has been punched, it is ejected or otherwise removed from the punch and die mechanism, typically by advancement of the next strip of wood into the mechanism.
While this technique for forming molded plastic articles with a wooden backing member has proven to greatly facilitate formation of these types of backed molded articles, the operation of the apparatus is not always completely trouble-free. Because the strips of wood from which the wooden backing members are cut are relatively thin and have precise tolerances, e.g., between 0.03 and 0.04 inch thick, and because the slots through which the backing members pass are also formed to precise tolerances, the strips of wood must be carefully guided and positioned in the mechanism in order to assure smooth operation. Additionally, jamming of the mechanism can sometimes occur when strips of wood fed into the machine are misaligned or have improper thickness. This is particularly true when the apparatus is operated such that a new strip of wood introduced into that mechanism engages a punched-out strip to eject the punched strip from the mechanism. Naturally, any jamming or other problems which result attendant to positioning of the wood strips in the device results in undesirable downtime for the entire apparatus. Additionally, even when automatic loading mechanisms are provided for feeding the discrete strips of wood into the machine, such loading devices usually must be re-supplied with wood strips several times within the space of a work shift, thus resulting in non-productive downtime for the operation.
In view of the foregoing, it is particularly desirable to provide an apparatus and method for forming molded plastic articles, such as support devices, having fibrous backing members which obviates problems heretofore associated with formation of these articles by positioning of individual wooden strips in association with the plastic molding mechanism of the apparatus. Such an arrangement should preferably provide wooden or otherwise fibrous material in a continuous fashion so that downtime of the apparatus can be reduced to a minimum, and should also be arranged to minimize problems of jamming and the like which can occur attendant to feeding of discrete wood strips into the machine.